553 
The electrifying power’) on the other hand proved to be additive. 
The maximal charge of the single solutions, determined by Mr. 
VAN DER Biu?) appears to be per c.c. of sprayed solution: 
Terpineol. Guaiacol. Caproi aeid. 
1/, sat. (too great) '/, sat. 135.109 Coul. */, sat. 196.10-Coul. 
ASOR IT 5; RER AS, ‘3 
For the mixtures the charge per c.e. of sprayed solution is: 
Critical dist. Charge 
(for 0.9 ce.) (per c¢.c,) 
Terpineol-Guaiacol mixt. (4: 5) 60 ¢.m. 168.10—1° Coul. 
Terpineol-Caproic acid mixt. (1: 2) Bal; 200. 4 ne 
Guaiacol-Caproic acid mixt. (1:1) 260 ,, ye oe ‘5 
Regarding merely the odorous substances and neglecting the water 
the charge of the mixture would be too small; turning our attention 
to the water only and regarding the odorous substances merely as 
catalytic means, largely enhancing the initial ionization of the water, 
it would not be enough. The truth lies no doubt midway, since 
both the added odorous substances and the water are essential to 
bring about the electrical phenomenon, as measured by us. 
But in whatever way the quantitative measurement may be carried 
out, the electrical phenomenon is at all events additive, whereas the 
olfactory quality appears to be weaker (weakened in the liquid 
mixture, faded out altogether in the mixture of the odorous gases 
in the double olfactometer). 
From the foregoing it follows that in practice we are repeatedly 
confronted with fragrant matter of slight intensity, but of high electri-. 
fying power, when it is resolved in water and sprayed into a vapour. 
This will be the case, when it is built up of odorous substances 
which, when mixed, counteract each other in part, as to smell, but 
whose electrical effect is added together. 
When the mixed substances pass into a chemical combination it 
1) H. ZWAARDEMAKER, The Electrical Phenemenon in cloudlike condensed 
odorous Watervapours, examined in collaboration with Messrs H. Knoops and 
M. N. van Der Buu, see These Proceedings Vol. XIX p. 44. The electrical 
phenomenon of odorous substances is allied to, but notidentical with waterfall- 
electricity, for, apart from quantitative differences, our electrical phenomenon 
largely increases with a rise of temperature, whereas, according to LENARD, 
waterfall-electricity increases but little, and moreover the addition of salt augments 
vapour-electricity, whereas it diminishes true waterfall-electricity. 
2) All determinations were performed at an overpressure of two atm, with an 
earthed sprayer and at a critical distance. The latter was, with a spraying of 0.8 c.c. 
for 1/9 dil. terpineol solution 4 e.e.; for 1/9 dil. guaiacol solution 10 c.c.; for 
1’, dil. caproic acid solution 13 cc. 
